1. Field of the Invention
The present invention relates to a slide switch.
2. Description of the Related Art
Heretofore, there has been known a key interlock system which is designed, when a shift lever of a shifter mechanism of an automatic transmission vehicle is in a position other than a P (Parking) range position, to make it unable to pull out an engine key from a key cylinder even if the key is turned to a LOCK position (or OFF position) (see JP 8-233078A).
As illustrated in FIG. 3A, in the conventional key interlock system, a slide switch 2(A) is adapted to be set to an ON state in a manner interlocked with an operation of moving a shift lever 1 to a P range position, to thereby cause a key pull-out preventing solenoid 3 to be set to an ON state. This makes it possible to pull out an engine key 4 from a key cylinder 5. In this type of key interlock system, a large current (several hundred mA, e.g., 400 to 700 mA) is applied to the slide switch 2(A) to set the solenoid 3 to the ON state. Thus, the slide switch 2(A) is required to have a switch structure suitable for large current.
Meanwhile, in late years, a keyless engine starting system has been employed which is designed to allow an engine to be started without using the above mechanical engine key. In the keyless engine starting system, a driver can start the engine by sending a signal to the system from a signal transmitter section, such as a card carryable by the driver, and then performing a simple operation, such as an operation of turning a start switch.
For an emergency situation where no signal is transmitted from the signal transmitter section such as the card, due to battery exhaustion or the like, the keyless engine starting system comprises a simple engine key 4 as an adjunct to the card or the like. The driver can start the engine by turning this engine key 4 after inserting it into a key cylinder 5. In the keyless engine starting system, as shown in FIG. 3B, a slide switch 2(B) is adapted to be set to an ON state in an interlocked manner with the operation of moving the shift lever 1 to the P range position, to thereby cause the solenoid 3 to be set to the ON state through a switching element 7. This makes it possible to pull out the engine key 4 from the key cylinder 5.
Instead of playing a roll in directly setting the solenoid 3 to the ON state as in the slide switch 2(A) in the former type of key interlock system, the slide switch 2(B) in the latter type of key interlock system plays only a roll in outputting an ON signal to the switching element 7 via an ECU (Electric Control Unit) 6. Thus, in the latter type of key interlock system, a small current (a few mA to several ten mA, e.g., 3 to 10 mA) is applied to the slide switch 2(B) to indirectly set the solenoid 3 to the ON state. Thus, the slide switch 2(B) is required to have a switch structure suitable for small current.
If a small current is applied to the large-current slide switch 2(A), a contact failure between switch contacts is likely to occur due to an oxide film or the like. If a large current is applied to the small-current slide switch 2(B), switch contacts are likely to degrade due to arc discharge. Therefore, as the slide switch designed to be interlocked with the shifter mechanism, it is necessary for a vehicle having the former type of key interlock system to employ the large-current slide switch 2(A), and it is necessary for a vehicle having the latter type of key interlock system to employ the small-current slide switch 2(B).
However, in cases where the large-current slide switch 2(A) and the small-current slide switch 2(B) are selectively used depending on the types of key interlock systems, an operation of installing the slide switch will become complicated. Moreover, there is a risk that an operator wrongly selects the type of slide switch to be installed. Further, it is necessary to produce and manage the two types of slide switches, which leads to an increase in cost.